Concave cover plate



FIG. 1 is a front perspective view of a concave cover plate embodying my new design when mounted on an exemplary concave grate;

FIG. 2 is a front perspective view of the concave cover plate independent of the exemplary concave grate;

FIG. 3 is a right side elevation view thereof, of which the left side elevation view is a mirror image;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a front end elevation view thereof; and,

FIG. 7 is a rear end elevation view thereof.

The broken lines in the drawings illustrate portions of the concave cover plate and environmental structure of a grate that form no part of the claimed design. 

CLAIM The ornamental design for a concave cover plate, as shown and described. 